import java.util.Arrays;

public class Solution {
    //最长数队链
    public int findLongestChain(int[][] pairs) {
        // 预处理
        Arrays.sort(pairs, (a, b) -> a[0] - b[0]);
        int n = pairs.length;
        int[] dp = new int[n];
        for (int i = 0; i < n; i++) {
            dp[i] = 1;
        }
        int ret = 1;
        for (int i = 1; i < n; i++) {
            for (int j = 0; j < i; j++) {
                if (pairs[j][1] < pairs[i][0]) {
                    dp[i] = Math.max(dp[j] + 1, dp[i]);
                }
                if (dp[i] > ret) {
                    ret = dp[i];
                }
            }
        }
        return ret;
    }
}
